In a closed ecological system, any waste products produced by one species must be used by at least one other species. If the purpose is to maintain a life form, such as a mouse or a human, waste products such as carbon dioxide, feces and urine must eventually be converted into oxygen, food, and water.

A closed ecological system must contain at least one autotrophic organism. While both chemotrophic and phototrophic organisms are plausible, almost all closed ecological systems to date are based on a phototroph such as green algae.

The 1993 novel This Other Eden by Ben Elton featured the development of "claustrospheres" which were closed ecological systems contained within a dome in which people could take refuge in the event of environmental collapse.

The critically panned 1996 comedy film Bio-Dome involved the protagonists becoming trapped in a closed ecological system being run as an experiment.